Pakistani tribesmen hold banners as they march during a protest rally against US drone attacks, in Miranshah, the main town in North Waziristan district on January 21, 2011. Hundreds of Pakistani tribesmen paraded in the streets to demand an end to US drone attacks which they said were killing innocent people in the tribal areas, witnesses said. In 2010 the campaign doubled missile attacks in the tribal area with around 100 drone strikes killing more than 650 people, according to an AFP tally.

US officials today said the CIA drone strikes that hit Pakistan on Monday were after Al Qaeda's number two man, Abu Yahia al-Libi, The New York Times reported.

The BBC confirmed today that al-Libi was killed in the drone strikes in Pakistan, citing US officials. CNN also confirmed the news, noting that analysts view his death as a "cataclysmic blow" to the terrorist organization.

Al-Libi emerged as one of Al Qaeda's most prominent clerics and propagandists in recent years, according to CNN.

Local officials said the attacks, which hit the North Waziristan tribal region early Monday, killed at least 15 people, according to The New York Times, but US officials said only five people died.

Monday's missile assault was the third such strike in Pakistan in the last three days. The violence comes as the US prepares for delicate talks with Pakistan in the nation's capital, said The Times, with a top US defense department official set to arrive in Islamabad later this week.

Local officials earlier told The Times that Monday's attack is the most deadly attack in the region since November last year.

The attacks targeted a believed military compound in Hesokhel, near the North Waziristan capital of Miranshah. The area is considered rife with militant activity, reported BBC News.

The State Department was offering $1 million for help in tracking down Libyan native al-Libi, who escaped Afghanistan's Bagram Air Base in 2005 and was known for producing videos urging violence against the United States, said the Associated Press.

Pakistan has denounced US drone attacks as a violation of its sovereignty. The issue has severely strained US-Pakistani relations in recent months.

CBS News noted that the drone strikes have made a serious dent in the senior tanks of the Al Qaeda network, targeting dozens of top leaders in Pakistan and Yemen.

The killing of al-Libi on Pakistani soil "bolsters the CIA's push to continue the drone program despite the continued political resistance from Pakistan and collateral damage," former CIA officer Paul Pillar told the AP.